diff --git a/BeanCovertor.swift b/BeanCovertor.swift
index fb286dfcd..bbb869ac7 100644
--- a/BeanCovertor.swift
+++ b/BeanCovertor.swift
@@ -179,8 +179,8 @@ func mapToLiveTranscoding(_ map: Dictionary<String, Any>) -> AgoraLiveTranscodin
         transcoding.transcodingExtraInfo = userConfigExtraInfo
     }
     if let transcodingUsers = map["transcodingUsers"] as? Array<Any> {
-        transcodingUsers.forEach { (item) in
-            if let item = item as? Dictionary<String, Any> {
+        transcodingUsers.forEach {
+            if let item = $0 as? Dictionary<String, Any> {
                 transcoding.add(mapToTranscodingUser(item))
             }
         }
@@ -208,8 +208,8 @@ func mapToChannelMediaRelayConfiguration(_ map: Dictionary<String, Any>) -> Agor
         config.sourceInfo = mapToChannelMediaInfo(srcInfo)
     }
     if let destInfos = map["destInfos"] as? Array<Any> {
-        destInfos.forEach { (item) in
-            if let item = item as? Dictionary<String, Any> {
+        destInfos.forEach {
+            if let item = $0 as? Dictionary<String, Any> {
                 let info = mapToChannelMediaInfo(item)
                 config.setDestinationInfo(info, forChannelName: info.channelName ?? "")
             }
diff --git a/Callback.swift b/Callback.swift
index bf97af5c7..b911dfff8 100644
--- a/Callback.swift
+++ b/Callback.swift
@@ -17,14 +17,14 @@ protocol Callback: class {
 }
 
 extension Callback {
-    func code(_ code: Int32?, _ runnable: ((Int32) -> Any?)? = nil) {
+    func code(_ code: Int32?, _ runnable: ((Int32?) -> Any?)? = nil) {
         if code == nil || code! < 0 {
             let newCode = abs(Int(code ?? Int32(AgoraErrorCode.notInitialized.rawValue)))
             failure(String(newCode), AgoraRtcEngineKit.getErrorDescription(newCode) ?? "")
             return
         }
 
-        let res = runnable?(code!)
+        let res = runnable?(code)
         if res is Void {
             success(nil)
         } else {
diff --git a/Extensions.swift b/Extensions.swift
index d30ba931d..6f69f1596 100644
--- a/Extensions.swift
+++ b/Extensions.swift
@@ -144,8 +144,8 @@ extension AgoraRtcAudioVolumeInfo {
 extension Array where Element: AgoraRtcAudioVolumeInfo {
     func toMapList() -> Array<Dictionary<String, Any?>> {
         var list = [Dictionary<String, Any?>]()
-        self.forEach { (item) in
-            list.append(item.toMap())
+        self.forEach {
+            list.append($0.toMap())
         }
         return list
     }
@@ -187,8 +187,8 @@ extension AgoraFacePositionInfo {
 extension Array where Element: AgoraFacePositionInfo {
     func toMapList() -> Array<Dictionary<String, Any?>> {
         var list = [Dictionary<String, Any?>]()
-        self.forEach { (item) in
-            list.append(item.toMap())
+        self.forEach {
+            list.append($0.toMap())
         }
         return list
     }
diff --git a/MediaObserver.swift b/MediaObserver.swift
index d90734e4b..0e853048f 100644
--- a/MediaObserver.swift
+++ b/MediaObserver.swift
@@ -43,9 +43,7 @@ extension MediaObserver: AgoraMediaMetadataDataSource {
 extension MediaObserver: AgoraMediaMetadataDelegate {
     func receiveMetadata(_ data: Data, fromUser uid: Int, atTimestamp timestamp: TimeInterval) {
         emitter([
-            "buffer": String(data: data, encoding: .utf8),
-            "uid": uid,
-            "timeStampMs": timestamp
+            "data": [String(data: data, encoding: .utf8) ?? "", uid, timestamp]
         ])
     }
 }
diff --git a/RtcChannel.swift b/RtcChannel.swift
index b27ab8094..08944703c 100644
--- a/RtcChannel.swift
+++ b/RtcChannel.swift
@@ -134,8 +134,8 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     }
 
     func Release() {
-        rtcChannelMap.forEach { key, value in
-            value.destroy()
+        rtcChannelMap.forEach {
+            $1.destroy()
         }
         rtcChannelMap.removeAll()
         rtcChannelDelegateMap.removeAll()
@@ -149,10 +149,10 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     }
 
     @objc func create(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(params["engine"] as? AgoraRtcEngineKit) { [weak self] it in
-            if let rtcChannel = it.createRtcChannel(params["channelId"] as! String) {
-                let delegate = RtcChannelEventHandler() { [weak self] methodName, data in
-                    self?.emitter(methodName, data)
+        callback.resolve(params["engine"] as? AgoraRtcEngineKit) { [weak self] in
+            if let rtcChannel = $0.createRtcChannel(params["channelId"] as! String) {
+                let delegate = RtcChannelEventHandler() { [weak self] in
+                    self?.emitter($0, $1)
                 }
                 rtcChannel.setRtcChannelDelegate(delegate)
                 self?.rtcChannelMap[rtcChannel.getId()!] = rtcChannel
@@ -196,8 +196,8 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     }
 
     @objc func getConnectionState(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(self[params["channelId"] as! String]) { it in
-            it.getConnectionState().rawValue
+        callback.resolve(self[params["channelId"] as! String]) {
+            $0.getConnectionState().rawValue
         }
     }
 
@@ -210,8 +210,8 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     }
 
     @objc func getCallId(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(self[params["channelId"] as! String]) { it in
-            it.getCallId()
+        callback.resolve(self[params["channelId"] as! String]) {
+            $0.getCallId()
         }
     }
 
@@ -286,8 +286,8 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     @objc func registerMediaMetadataObserver(_ params: NSDictionary, _ callback: Callback) {
         var code = -AgoraErrorCode.notInitialized.rawValue
         if let it = self[params["channelId"] as! String] {
-            let mediaObserver = MediaObserver { [weak self] data in
-                self?.emitter(RtcEngineEvents.MetadataReceived, data)
+            let mediaObserver = MediaObserver { [weak self] in
+                self?.emitter(RtcEngineEvents.MetadataReceived, $0)
             }
             if it.setMediaMetadataDelegate(mediaObserver, with: .video) {
                 mediaObserverMap[it.getId()!] = mediaObserver
@@ -309,14 +309,14 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
     }
 
     @objc func setMaxMetadataSize(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(mediaObserverMap[params["channelId"] as! String]) { it in
-            it.setMaxMetadataSize(params["size"] as! Int)
+        callback.resolve(mediaObserverMap[params["channelId"] as! String]) {
+            $0.setMaxMetadataSize(params["size"] as! Int)
         }
     }
 
     @objc func sendMetadata(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(mediaObserverMap[params["channelId"] as! String]) { it in
-            it.addMetadata(params["metadata"] as! String)
+        callback.resolve(mediaObserverMap[params["channelId"] as! String]) {
+            $0.addMetadata(params["metadata"] as! String)
         }
     }
 
@@ -356,7 +356,7 @@ class RtcChannelManager: NSObject, RtcChannelInterface {
         if let it = self[params["channelId"] as! String] {
             code = it.createDataStream(&streamId, reliable: params["reliable"] as! Bool, ordered: params["ordered"] as! Bool)
         }
-        callback.code(code) { it in
+        callback.code(code) { ignore in
             streamId
         }
     }
diff --git a/RtcChannelEvent.swift b/RtcChannelEvent.swift
index 19b7367cd..47144ae9a 100644
--- a/RtcChannelEvent.swift
+++ b/RtcChannelEvent.swift
@@ -220,23 +220,23 @@ extension RtcChannelEventHandler: AgoraRtcChannelDelegate {
     public func rtcChannel(_ rtcChannel: AgoraRtcChannel, didReceive event: AgoraChannelMediaRelayEvent) {
         callback(RtcChannelEvents.ChannelMediaRelayEvent, rtcChannel, event.rawValue)
     }
-    
+
     func rtcChannel(_ rtcChannel: AgoraRtcChannel, didAudioPublishStateChange oldState: AgoraStreamPublishState, newState: AgoraStreamPublishState, elapseSinceLastState: Int) {
         callback(RtcChannelEvents.AudioPublishStateChanged, rtcChannel, rtcChannel.getId(), oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcChannel(_ rtcChannel: AgoraRtcChannel, didVideoPublishStateChange oldState: AgoraStreamPublishState, newState: AgoraStreamPublishState, elapseSinceLastState: Int) {
         callback(RtcChannelEvents.VideoPublishStateChanged, rtcChannel, rtcChannel.getId(), oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcChannel(_ rtcChannel: AgoraRtcChannel, didAudioSubscribeStateChange uid: UInt, oldState: AgoraStreamSubscribeState, newState: AgoraStreamSubscribeState, elapseSinceLastState: Int) {
         callback(RtcChannelEvents.AudioSubscribeStateChanged, rtcChannel, rtcChannel.getId(), uid, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcChannel(_ rtcChannel: AgoraRtcChannel, didVideoSubscribeStateChange uid: UInt, oldState: AgoraStreamSubscribeState, newState: AgoraStreamSubscribeState, elapseSinceLastState: Int) {
         callback(RtcChannelEvents.VideoSubscribeStateChanged, rtcChannel, rtcChannel.getId(), uid, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcChannel(_ rtcChannel: AgoraRtcChannel, rtmpStreamingEventWithUrl url: String, eventCode: AgoraRtmpStreamingEvent) {
         callback(RtcChannelEvents.RtmpStreamingEvent, rtcChannel, url, eventCode.rawValue)
     }
diff --git a/RtcEngine.swift b/RtcEngine.swift
index 08d787163..c3921c735 100644
--- a/RtcEngine.swift
+++ b/RtcEngine.swift
@@ -51,7 +51,7 @@ protocol RtcEngineInterface:
     func enableWebSdkInteroperability(_ params: NSDictionary, _ callback: Callback)
 
     func getConnectionState(_ callback: Callback)
-    
+
     func sendCustomReportMessage(_ params: NSDictionary, _ callback: Callback)
 
     func getCallId(_ callback: Callback)
@@ -67,7 +67,7 @@ protocol RtcEngineInterface:
     func setLogFileSize(_ params: NSDictionary, _ callback: Callback)
 
     func setParameters(_ params: NSDictionary, _ callback: Callback)
-    
+
     func getNativeHandle(_ callback: Callback)
 }
 
@@ -366,8 +366,8 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func create(_ params: NSDictionary, _ callback: Callback) {
-        delegate = RtcEngineEventHandler() { [weak self] methodName, data in
-            self?.emitter(methodName, data)
+        delegate = RtcEngineEventHandler() { [weak self] in
+            self?.emitter($0, $1)
         }
         let config = AgoraRtcEngineConfig()
         config.appId = params["appId"] as? String
@@ -377,7 +377,7 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func destroy(_ callback: Callback) {
-        callback.resolve(engine) { [weak self] it in
+        callback.resolve(engine) { [weak self] ignore in
             self?.Release()
         }
     }
@@ -416,18 +416,18 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func getConnectionState(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.getConnectionState().rawValue
+        callback.resolve(engine) {
+            $0.getConnectionState().rawValue
         }
     }
-    
+
     @objc func sendCustomReportMessage(_ params: NSDictionary, _ callback: Callback) {
         callback.code(engine?.sendCustomReportMessage(params["id"] as! String, category: params["category"] as! String, event: params["event"] as! String, label: params["label"] as! String, value: params["value"] as! Int))
     }
 
     @objc func getCallId(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.getCallId()
+        callback.resolve(engine) {
+            $0.getCallId()
         }
     }
 
@@ -450,10 +450,10 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     @objc func setLogFileSize(_ params: NSDictionary, _ callback: Callback) {
         callback.code(engine?.setLogFileSize((params["fileSizeInKBytes"] as! UInt)))
     }
-    
+
     @objc func getNativeHandle(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            Int(bitPattern: it.getNativeHandle())
+        callback.resolve(engine) {
+            Int(bitPattern: $0.getNativeHandle())
         }
     }
 
@@ -470,14 +470,14 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func getUserInfoByUserAccount(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.getUserInfo(byUserAccount: params["userAccount"] as! String, withError: nil)?.toMap()
+        callback.resolve(engine) {
+            $0.getUserInfo(byUserAccount: params["userAccount"] as! String, withError: nil)?.toMap()
         }
     }
 
     @objc func getUserInfoByUid(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.getUserInfo(byUid: params["uid"] as! UInt, withError: nil)?.toMap()
+        callback.resolve(engine) {
+            $0.getUserInfo(byUid: params["uid"] as! UInt, withError: nil)?.toMap()
         }
     }
 
@@ -602,26 +602,26 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func getAudioMixingPlayoutVolume(_ callback: Callback) {
-        callback.code(engine?.getAudioMixingPlayoutVolume()) { it in
-            it
+        callback.code(engine?.getAudioMixingPlayoutVolume()) {
+            $0
         }
     }
 
     @objc func getAudioMixingPublishVolume(_ callback: Callback) {
-        callback.code(engine?.getAudioMixingPublishVolume()) { it in
-            it
+        callback.code(engine?.getAudioMixingPublishVolume()) {
+            $0
         }
     }
 
     @objc func getAudioMixingDuration(_ callback: Callback) {
-        callback.code(engine?.getAudioMixingDuration()) { it in
-            it
+        callback.code(engine?.getAudioMixingDuration()) {
+            $0
         }
     }
 
     @objc func getAudioMixingCurrentPosition(_ callback: Callback) {
-        callback.code(engine?.getAudioMixingCurrentPosition()) { it in
-            it
+        callback.code(engine?.getAudioMixingCurrentPosition()) {
+            $0
         }
     }
 
@@ -634,8 +634,8 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func getEffectsVolume(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.getEffectsVolume()
+        callback.resolve(engine) {
+            $0.getEffectsVolume()
         }
     }
 
@@ -682,10 +682,10 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     @objc func resumeAllEffects(_ callback: Callback) {
         callback.code(engine?.resumeAllEffects())
     }
-    
+
     @objc func setAudioSessionOperationRestriction(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.setAudioSessionOperationRestriction(AgoraAudioSessionOperationRestriction(rawValue: params["restriction"] as! UInt))
+        callback.resolve(engine) {
+            $0.setAudioSessionOperationRestriction(AgoraAudioSessionOperationRestriction(rawValue: params["restriction"] as! UInt))
         }
     }
 
@@ -762,8 +762,8 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func isSpeakerphoneEnabled(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.isSpeakerphoneEnabled()
+        callback.resolve(engine) {
+            $0.isSpeakerphoneEnabled()
         }
     }
 
@@ -825,11 +825,11 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
 
     @objc func registerMediaMetadataObserver(_ callback: Callback) {
         var code = -AgoraErrorCode.notInitialized.rawValue
-        if let it = engine {
-            let mediaObserver = MediaObserver { [weak self] data in
-                self?.emitter(RtcEngineEvents.MetadataReceived, data)
+        if let `engine` = engine {
+            let mediaObserver = MediaObserver { [weak self] in
+                self?.emitter(RtcEngineEvents.MetadataReceived, $0)
             }
-            if it.setMediaMetadataDelegate(mediaObserver, with: .video) {
+            if engine.setMediaMetadataDelegate(mediaObserver, with: .video) {
                 self.mediaObserver = mediaObserver
                 code = AgoraErrorCode.noError.rawValue
             }
@@ -849,14 +849,14 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func setMaxMetadataSize(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(mediaObserver) { it in
-            it.setMaxMetadataSize(params["size"] as! Int)
+        callback.resolve(mediaObserver) {
+            $0.setMaxMetadataSize(params["size"] as! Int)
         }
     }
 
     @objc func sendMetadata(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(mediaObserver) { it in
-            it.addMetadata(params["metadata"] as! String)
+        callback.resolve(mediaObserver) {
+            $0.addMetadata(params["metadata"] as! String)
         }
     }
 
@@ -911,14 +911,14 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func isCameraZoomSupported(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.isCameraZoomSupported()
+        callback.resolve(engine) {
+            $0.isCameraZoomSupported()
         }
     }
 
     @objc func isCameraTorchSupported(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.isCameraTorchSupported()
+        callback.resolve(engine) {
+            $0.isCameraTorchSupported()
         }
     }
 
@@ -927,20 +927,20 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func isCameraExposurePositionSupported(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.isCameraExposurePositionSupported()
+        callback.resolve(engine) {
+            $0.isCameraExposurePositionSupported()
         }
     }
 
     @objc func isCameraAutoFocusFaceModeSupported(_ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.isCameraAutoFocusFaceModeSupported()
+        callback.resolve(engine) {
+            $0.isCameraAutoFocusFaceModeSupported()
         }
     }
 
     @objc func setCameraZoomFactor(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.setCameraZoomFactor(CGFloat(params["factor"] as! Float))
+        callback.resolve(engine) {
+            $0.setCameraZoomFactor(CGFloat(params["factor"] as! Float))
             return nil
         }
     }
@@ -950,15 +950,15 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func setCameraFocusPositionInPreview(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            engine?.setCameraFocusPositionInPreview(CGPoint(x: params["positionX"] as! Double, y: params["positionY"] as! Double))
+        callback.resolve(engine) {
+            $0.setCameraFocusPositionInPreview(CGPoint(x: params["positionX"] as! Double, y: params["positionY"] as! Double))
             return nil
         }
     }
 
     @objc func setCameraExposurePosition(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.setCameraExposurePosition(CGPoint(x: params["positionXinView"] as! Double, y: params["positionYinView"] as! Double))
+        callback.resolve(engine) {
+            $0.setCameraExposurePosition(CGPoint(x: params["positionXinView"] as! Double, y: params["positionYinView"] as! Double))
             return nil
         }
     }
@@ -968,15 +968,15 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
     }
 
     @objc func setCameraTorchOn(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.setCameraTorchOn(params["isOn"] as! Bool)
+        callback.resolve(engine) {
+            $0.setCameraTorchOn(params["isOn"] as! Bool)
             return nil
         }
     }
 
     @objc func setCameraAutoFocusFaceModeEnabled(_ params: NSDictionary, _ callback: Callback) {
-        callback.resolve(engine) { it in
-            it.setCameraAutoFocusFaceModeEnabled(params["enabled"] as! Bool)
+        callback.resolve(engine) {
+            $0.setCameraAutoFocusFaceModeEnabled(params["enabled"] as! Bool)
         }
     }
 
@@ -990,7 +990,7 @@ class RtcEngineManager: NSObject, RtcEngineInterface {
         if let it = engine {
             code = it.createDataStream(&streamId, reliable: params["reliable"] as! Bool, ordered: params["ordered"] as! Bool)
         }
-        callback.code(code) { it in
+        callback.code(code) { ignore in
             streamId
         }
     }
diff --git a/RtcEngineEvent.swift b/RtcEngineEvent.swift
index f303ef5a1..ed926d7d0 100644
--- a/RtcEngineEvent.swift
+++ b/RtcEngineEvent.swift
@@ -469,31 +469,31 @@ extension RtcEngineEventHandler: AgoraRtcEngineDelegate {
     public func rtcEngineVideoDidStop(_ engine: AgoraRtcEngineKit) {
         callback(RtcEngineEvents.VideoStopped)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, firstLocalAudioFramePublished elapsed: Int) {
         callback(RtcEngineEvents.FirstLocalAudioFramePublished, elapsed)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, firstLocalVideoFramePublished elapsed: Int) {
         callback(RtcEngineEvents.FirstLocalVideoFramePublished, elapsed)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, didAudioPublishStateChange channel: String, oldState: AgoraStreamPublishState, newState: AgoraStreamPublishState, elapseSinceLastState: Int) {
         callback(RtcEngineEvents.AudioPublishStateChanged, channel, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, didVideoPublishStateChange channel: String, oldState: AgoraStreamPublishState, newState: AgoraStreamPublishState, elapseSinceLastState: Int) {
         callback(RtcEngineEvents.VideoPublishStateChanged, channel, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, didAudioSubscribeStateChange channel: String, withUid uid: UInt, oldState: AgoraStreamSubscribeState, newState: AgoraStreamSubscribeState, elapseSinceLastState: Int) {
         callback(RtcEngineEvents.AudioSubscribeStateChanged, channel, uid, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, didVideoSubscribeStateChange channel: String, withUid uid: UInt, oldState: AgoraStreamSubscribeState, newState: AgoraStreamSubscribeState, elapseSinceLastState: Int) {
         callback(RtcEngineEvents.VideoSubscribeStateChanged, channel, uid, oldState.rawValue, newState.rawValue, elapseSinceLastState)
     }
-    
+
     func rtcEngine(_ engine: AgoraRtcEngineKit, rtmpStreamingEventWithUrl url: String, eventCode: AgoraRtmpStreamingEvent) {
         callback(RtcEngineEvents.RtmpStreamingEvent, url, eventCode.rawValue)
     }
diff --git a/RtcSurfaceView.swift b/RtcSurfaceView.swift
index cd69a26b7..9ae740cab 100644
--- a/RtcSurfaceView.swift
+++ b/RtcSurfaceView.swift
@@ -14,23 +14,27 @@ class RtcSurfaceView: UIView {
     private var surface: UIView
     private var canvas: AgoraRtcVideoCanvas
     private weak var channel: AgoraRtcChannel?
-    
+
     override init(frame: CGRect) {
-        surface = UIView(frame: frame)
+        surface = UIView(frame: CGRect(origin: CGPoint(x: 0, y: 0), size: frame.size))
         canvas = AgoraRtcVideoCanvas()
         canvas.view = surface
         super.init(frame: frame)
         addSubview(surface)
-        addObserver(self, forKeyPath: "frame", options: .new, context: nil)
+        addObserver(self, forKeyPath: observerForKeyPath(), options: .new, context: nil)
+    }
+
+    func observerForKeyPath() -> String {
+        return "frame"
     }
-    
+
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
-    
+
     deinit {
         canvas.view = nil
-        removeObserver(self, forKeyPath: "frame", context: nil)
+        removeObserver(self, forKeyPath: observerForKeyPath(), context: nil)
     }
 
     func setData(_ engine: AgoraRtcEngineKit, _ channel: AgoraRtcChannel?, _ uid: Int) {
@@ -56,8 +60,10 @@ class RtcSurfaceView: UIView {
     }
 
     private func setupVideoCanvas(_ engine: AgoraRtcEngineKit) {
-        subviews.forEach { $0.removeFromSuperview() }
-        surface = UIView(frame: self.frame)
+        subviews.forEach {
+            $0.removeFromSuperview()
+        }
+        surface = UIView(frame: CGRect(origin: CGPoint(x: 0, y: 0), size: bounds.size))
         addSubview(surface)
         canvas.view = surface
         if canvas.uid == 0 {
@@ -88,10 +94,12 @@ class RtcSurfaceView: UIView {
             }
         }
     }
-    
-    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
-        if keyPath == "frame" {
-            surface.frame = CGRect(x: 0, y: 0, width: self.frame.width, height: self.frame.height)
+
+    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey: Any]?, context: UnsafeMutableRawPointer?) {
+        if keyPath == observerForKeyPath() {
+            if let rect = change?[.newKey] as? CGRect {
+                surface.frame = CGRect(origin: CGPoint(x: 0, y: 0), size: rect.size)
+            }
         }
     }
 }